947
ACUS48 KWNS 080811
SWOD48
SPC AC 080810

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0310 AM CDT Wed Oct 08 2025

Valid 111200Z - 161200Z

...DISCUSSION...
An upper ridge over the Plains on Day 4/Sat will shift eastward
toward the Mid/Lower MS Valley on Day 5/Sun as an upper shortwave
trough over the Great Basin ejects northeast across the
northern/central Plains. Surface cyclogenesis will deepen across the
Dakotas as this occurs, and a cold front will sweep east across the
northern/central Plains to the Upper Midwest by early Day 6/Mon.
Modest boundary layer moisture will be in place ahead of the cold
front, with severe potential likely limited by weak instability and
poor lapse rates.

Spread among medium range guidance increases by Days 6-8/Mon-Wed.
Some guidance maintains a upper trough/closed low over the eastern
U.S. early next week, maintaining an upper ridge over the central
U.S. while another trough deepens over the west. Other guidance is
more progressive, with the eastern trough moving offshore, allowing
the western trough will sweep east into the Plains by the end of the
period. Regardless of the exact evolution that unfolds, southerly
low-level flow across the Plains will allow for at least modest
moisture return into the southern/central Plains, increasing
thunderstorm potential. However, uncertainty precludes severe
probabilities at this time.

..Leitman.. 10/08/2025